This invention relates to a circuit for testing for transient abnormalities of the rotor suspension electronis of a gyroscope, and more particularly to system in which faults are isolated and recorded for later analysis.
An electrostatic gyroscope is a free rotor type of gyroscope in which the rotor support forces are derived from an electric field. The rotor is generally an aluminum or beryllium sphere which may be either solid or hollow. The electrostatic support consists generally of a plurality of pairs of spherical segment electrodes or plates dispersed about the rotor.
One development in electrostatic gyroscope suspension systems is the use of a mass unbalanced rotor, instead of induction pickoff schemes, to obtain attitude readout. See for example a paper entitled "Electrostatic Gyro Operation and Application" presented by Rockwell International at the Institute of Navigation Thirty-Fourth Annual meeting June 26-29, 1978, Arlington, Va. and two U.S. Pat. Nos. 3,697,143 and 3,955,426 to Klinchuch, assigned to Rockwell. The paper and two patents are incorporated by reference.
Attitude is the relative orientation of the spin axis of the rotor to, for example, the case housing of the rotor. Attitute readout can be obtained by detecting the amplitude of the modulation of the electrode voltages caused by the mass unbalance rotor as it spins around its spin axis. The plate voltgage modulation results from thependulosity of the rotor, which causes the gap to change between the rotor and the plate electrodes as the rotor is spinning. The maximum plate modulation occurs in the plane of the rotating pendulosity vector. Thus, the pickoff signal consists of two signal components, a servo signal indicative of the linear displacement of the rotor and a mass unbalance modulation signal resulting from the pendulosity of the spinning rotor.